Baler

ABSTRACT

A baler is disclosed having a safety gate which closes the access opening between the upper edge of the baling chamber and the press platen when the latter commences to descend and causes the baler to abort should there be any obstruction preventing full closure of the gate. Also shown is a single door baling chamber and a fluid pressure mechanism for locking the baling chamber door. In addition, there is disclosed a second or auxiliary manually operated safety gate with means preventing descent of the platen unless said gate is fully closed.

United States Patent 1191 Considine et al.

14 1 Jan. 21, 1975 1 BALER [75] Inventors: Robert W. Considine, Detroit; John W. Arthurs, Pontiac, both of Mich.

[73] Assignee: Bra-Con Industries, Inc., Livonia,

Mich.

22 Filed: Nov. 21, 1972 21 Appl. No.: 308,472

Related US. Application Data [63] Continuation-in-part of Ser. No. 132,090, April 7,

1971, abandoned.

[52] US. Cl 100/53, 100/3, 100/52, 100/218, 100/245, 100/255, 100/269 R,

[51] Int. Cl B30b 15/26 [58] Field of Search 292/33, 144; 100/52, 3, [00/53, 214, 218, 245, 269 R; 74/612, 613,

[56] References Cited UNITED STATES PATENTS 2 030,976 2/1936 Fairfielrl et al. 192/134 3,130,665 4/1964 Neitzel 100/53 3,352,230 11/1967 Hunnicutt... 100/53 3,602,136 8/1971 Ligh 100/53 Primary Examiner-Billy J. Wilhite Attorney, Agent, or Firm-Burton & Parker [5 7] ABSTRACT A baler is disclosed having a safety gate which closes the access opening between the upper edge of the baling chamber and the press platen when the latter commences to descend and causes the baler to abort should there be any obstruction preventing full closure of the gate. Also shown is a single door baling chamber and a fluid pressure mechanism for locking the baling chamber door. In addition, there is disclosed a second or auxiliary manually operated safety gate with means preventing descent of the platen unless said gate is fully closed.

8 Claims, 13 Drawing Figures PATENTED W21 5 SHEET 2 BF 8 Fl G 3 ATTORNEYS PATENTED 2 7 3', 861 .297

- sum u or 8 200 FIG.6

ATTORNEYS PATENTED m1 ms SHEH 7 0F 8 PATENIEU m2] m5 SHEEI 8 BF 8 F'lGmli BALER CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of our prior application, Ser. No. 132,090, filed Apr. 7, 1971 now abandoned.

FIELD OF INVENTION This invention relates to balers for wastepaper, cardboard boxes and other material.

BACKGROUND OF THE INVENTION Retail stores, such as supermarkets, have encountered an increasingly serious problem in disposing of shipping cartons in which goods are delivered. The receiving dock and receiving room of such establishments become cluttered with the empty boxes and cartons and the same are thereupon often piled outside in great disarray where they and their packing material contents may become scattered over and disfigure the outlying property. This invention relates to balers particularly well suited for use in such establishments as it enables the wastepaper, cardboard boxes and the like to be reduced in size to compact secure bales which may be stored in a small space until removal from the premises.

DESCRIPTION OF THE PRIOR ART Balers for paper, cardboard boxes and the like are commercially available and are also illustrated in the following United States Pat. Nos.:

SUMMARY OF INVENTION In a baler having a baling chamber with a vertically reciprocating press platen as disclosed by the above prior art, the baler is loaded when the platen is in its uppermost position by throwing the boxes or other material to be baled into the baling chamber over the upper edge thereof and when the chamber is filled, the press platen is caused to descend into the chamber to compact the material. This sequence may be repeated at number of times before a full size bale is formed. To prevent injury to the operator or those in the vicinity, a gate may be provided for the access opening at the upper edge of the baling chamber which must be closed before the press platen will descend. Heretofore this gate has been manually operable both for closing and opening movements.

A principal object of this invention is to provide a baler which is automatic in operation in that when the baling chamber is full of boxes or waste material to be compacted, the operator merely operates an initiation switch and thereafter the baler will close the safety gate, compact the material in the baling chamber, and then open the gate for deposit of additional material for compacting in making up a bale. To avoid possible injury to personnel or to the baler, the safety gate and baler are so constructed and arranged that the baler will not function to compact material in the baling chamber unless the safety gate is fully closed. If during automatic operation of the baler the safety gate does not fully close, operation of the baler is aborted.

Another object of the invention is the provision of a baler having a single door baling compartment and an automatic lock for such door.

Other objects and advantages of the invention will become apparent as the description proceeds.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front elevation of a baler embodying the invention showing the press platen lowering and the safety gate (broken away for clarity of disclosure of the press platen) fully closed across the material access opening;

FIG. 2 is an end elevation looking in the direction of arrow 2 in FIG. 1;

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 1 and FIG. 6 but with the gate only partially closed during descent of the platen;

FIG. 4 is a top view of the baler showing the baling chamber door open;

FIG. 5 is a view taken on the line 5-5 of FIG. 1 showing a form of baler chamber door locking mechanism;

FIG. 6 shows a completed bale in the baling chamber, the chamber door being open, and the bale ready for removal from the chamber;

FIG. 7 is a cross-sectional view taken along the line 77 of FIG. 6, showing mechanism for removing a bale from the baling chamber;

FIG. 8 is a fragmentary front elevation of the baler showing the gate and platen descending or ascending;

FIG. 9 is a schematic diagram of the fluid pressure circuit for the press platen ram;

FIG. 10 is a schematic diagram of the press platen ram control circuits;

FIG. 11 is a front elevation of a baler similar to FIG. 1 showing a modification in which a second safety gate is shown fully closed and the press platen and first safety gate are shown in the open position;

FIG. 12 is a cross-sectional view taken along the line l2l2 of FIG. 11 showing the platen and first safety gate lowering; and

FIG. 13 is a partial perspective of the second safety gate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawings, the baler includes a base formed by a rectangular arrangement of members 22, 24, 26 and 28 welded together at the corners and over which are laid and welded a plurality of members 30 forming the bottom or bed of the baling chamber 32. At intervals members 30 are spaced apart to provide baling wire receiving slots 31. Four columns 34, 36, 38 and 40 are secured to the corners of the base 20 and extend upwardly to and are secured to a rectangular frame comprising channel members 42, 44, 46 and 48 which are bridged by cross members 50 and 52 as shown in FIG. 4. An hydraulic ram 54 is secured to the cross members with a piston rod 56 depending therefrom and secured to a press platen 58 which reciprocates vertically under the influence of the ram through the open top of the baling chamber.

In addition to the bed or floor, the baling chamber includes four walls 60, 62, 64 and 66, (see FIG. 4), two of which, and 62, comprise an L-shaped door 68 hinged at one edge by offset hinges 70 to the adjacent edge of the door opening, as to the column 36. The

door and fixed walls of the chamber are strongly constructed. In the case of the door, horizontal channel members 72, 74, 76 and 78 have vertical steel panels 80 and 81 welded to them as shown in FIGS. 3 and 5. End wall 64 is similarly constructed with its horizontal members extending between and welded to columns 36 and 38. Back wall 38 comprises horizontal channels 82, 84 and 86 (FIG. 3) welded to and extending between columns 38 and 40, with a plurality of vertically extending members 88 welded to the horizontal channels and forming the inner surface of the back wall of the chamber. Corresponding to the arrangement of the floor members 30, some of the members 80 are welded together and others are spaced apart laterally to provide vertical bale wire slots 90 therebetween aligned with the slots 31.

The baling chamber offset hinges 70 allow the door to swing away from a compressed bale of material without binding thereagainst thus enabling the door to be swung open easily to the position shown in FIG. 4. Locking means is provided for locking the door closed. While a variety of locking devices may be employed, a power lock is shown in FIG. comprising a vertically floating fluid pressure cylinder 92 having a piston rod 94 at one end and a fixed rod 96 rigid with the cylinder at the opposite end. The rods are provided with locking pins 95 and 97 slidably received through aligned apertured lugs 98, 100 and 104 and 106 welded to the back wall 38 of the chamber. Rod 94 is slidably received through guide lug 102 also welded to the back wall. A pair oflugs 108 and 1 secured to the edge of the door 68 interfit with lugs 98, 100 and 104, 106 when the door is closed, and pins 95 and 97 will project through the aligned holes of the lugs as shown in FIG. 5. Upon pressurization of cylinder 92 to retract piston rod 94, pin 95 is drawn downwardly out of engagement with lug 108 and abuts lug 102 whereupon the cylinder ascends pulling pin 97 from engagement with lug 110. Reverse pressurization of cylinder will extend the pins to lock the door. Any suitable abutment 111 on pin 97 will prevent the cylinder from dropping further.

A door switch 112, see FIG. 3, is mounted on a portion 113 of the frame of the baler and has an actuator arm 114 which engages the door 68 when the same is completely closed. The switch is connected in the control circuit for the ram as schematically shown in FIG. 10, and prevents normal operation of the baler when the door 68 is other than fully closed.

The press platen comprises a pair of I-beams 116 and 118 (FIG. 3) to the undersides of which is welded a rectangular plate 120 to the upper side of which is secured the lower end of the piston rod 56. To the underside of plate 120 are secured a plurality of members 122 some of which are laterally spaced apart to provide bale wire receiving channels 124 aligned with the channels 90 in the back wall and the channels 31 is the bed. Four upstanding guides, one at each corner of plate 120, are secured thereto to move vertically with the platen. Three of the guides are shown at 126, 128 and 132 in FIGS. 3 and 8. The guides ride the inside angle of four L-channels 134, 136, 138 and 140 (FIG. 4) secured to the baler frame, which with the guides serve to guide the platen during its reciprocation. Suitable diagonal bracing 142 extends between the l-beams 116 and 118 and the four guides.

In FIG. 8 the platen 58 is shown at its uppermost position where it is spaced above the upper edge 144 of the door 68 to provide an access opening 146 therebetween, through which the material to be baled in the chamber may be thrown into the chamber. To prevent injury to the operator or others in the vicinity of the baler during its operation, a safety gate 148 is provided. The gate comprises a rectangular frame which may include top and bottom members 150 and 152 connected together by vertical members 154, 156, 158 160 and 162, with an expanded metal or other screen 164 secured to the frame in overlying relation. The gate is vertically reciprocable across the access opening in opposed U-channels 166 and 168, secured to the baler frame. Lugs 170, 172, 174 and 176 secured to the gate frame ride in such channels to guide movement of the gate.

In FIG. 8 the safety gate is shown fully open and it will be noted the lower edge of the gate is spaced below the lower face of the platen. I have found that if the gate extends below the platen by about 4 to 6 inches, this is adequate for the purpose hereinafter explained. In FIG. 1 the gate is shown as fully closed and the platen is just entering the baling chamber. To shift the gate between open and closed positions, it is coupled to the platen by means which include a lost motion coupling operable during ascent of the platen to open the gate, and during descent to close the gate and affording relative motion between the gate and platen as hereinafter explained. During descent of the platen from its uppermost position shown in FIG. 8, the gate descends with, but in advance of the platen, until the access opening is closed by the gate. Once the gate is closed, continued descent of the platen into the baling chamber involves movement relative to the gate because downward movement of the gate at its closed position is arrested by the closed lower ends of the gate guide channels 166 and 168, one of which closed ends is shown at 178 in FIG. 3. Following the compacting or downward movement of the platen into the baling chamber, and during ascent thereof, the gate is raised from its closed position and during upward gate travel, before the platen reaches the last stage of its upward travel, the relationship of the gate and platen is as shown in FIG. 3. When finally the platen again reaches the upper limit of its travel, the gate assumes its fully open position shown in FIG. 8.

The means coupling the gate to the platen for the aforesaid movement includes a pair of inwardly projecting lugs 180 and 182 (see FIGS. 3 and 8) affixed to the back side of the gate on vertical members 156 and 158 and adapted to rest on the top of the platen 58 to support the gate for ascent and descent with the platen while allowing relative movement therebetween.

During descent of the platen from its uppermost position of FIG. 8, should there be an obstruction in the access opening 146 that will prevent full closing of the gate, such as the obstruction shown in phantom outlined at 0 in FIG. 3, between the upper edge 144 of the baling chamber and the descending platen 58, which would be crushed therebetween, the safety gate 148, moving with but in advance of the platen, will strike the obstruction and descent of the gate will be thereby arrested and as the platen continues to descend relative movement of the platen downwardly in relation to the gate will occur. Such relative motion prior to full closure of the gate is advantageously utilized to actuate an abort switch LS-2 mounted on the platen as shown in FIG. 3 to be tripped by an actuating finger 194 mounted on and projecting laterally toward the platen from the gate to engage the actuating arm 196 of the switch. With gate descent arrested by the obstruction 0, continued descent of the platen tends to carry the arm 196 of switch LS-2 out of engagement with the laterally projecting finger 194 to trip the switch and cause an opening and closing of switch contacts as hereinafter described. Immediately upon tripping switch LS-2, when the gate is not in the fully closed position, descent of the platen is interrupted, and the platen is caused to ascend to its upper position lifting the gate off the obstruction and returning it to its fully open position. This is referred to as an abort and will occur before the platen comes into contact with the obstruction. The relative position of the switch LS-2 and the finger 194 may be predetermined so that only a small downward movement of the platen relative to the gate, considerably less than the 4 to 6 inch projection of the gate below the platen, will trip the switch causing an abort of the platen movement.

A safety gate override switch LS-l is also provided so that when the gate fully closes duing descent of the platen, and relative movement occurs therebetween, LS-2 will not cause an abort. LS-l is mounted on the frame of the baler adjacent the gate, as schematically shown in FIGS. 1 and 3. It has a trip arm 184 which engages a cam 186 mounted on the gate when the gate is fully closed to cause opening of the switch contacts with the resulting function hereinafter explained.

In FIGS. 9 and 10 pertinent portions of the hydraulic and electric circuitry of the baler are respectively shown. An hydraulic pump 250, operated by an electric motor 251, delivers fluid pressure to the ram 54 through a spring loaded four-way valve 252 having an actuating solenoid 254, and through a counterbalance valve 256 which prevents the platen from dropping when the pump motor 251 is shut off. A pressure relief valve 258 passes fluid pressure to the reservoir when the piston reaches the upper limit of its travel or if for some reason there should be a pressure rise in the outlet of the pump beyond the setting of this valve. A pressure response switch 260 serves to energize relay C to open normally closed relay contacts C-3 to de-energize solenoid 254 (see FIG. 10) and cause ascent of the platen when a predetermined compacting pressure is applied to the material beind compacted in the baling chamber.

In FIG. 10 the pump motor 251 is shown connected across the power mains 262 under control of a conventional motor relay starter M which is energized by momentarily closing the start switch in the control circuit inductively coupled at 264 to the mains. LS-l, which is tripped when the gate is fully closed, has a set of contacts N.O., H.C. that are closed when the gate is fully closed, and a set of contacts N.C., H.O. that are held open when the gate is closed. The safety switch LS-2 has a set of contacts N.C., I-I.O. that are held open when the platen is in its uppermost position or during descent of the platen before the gate either fully closes or encounters an obstruction. Should the gate encounter an obstruction before LS-l is tripped by cam 186, the contacts of LS-2 will close energizing relay C which will result in de-energization of solenoid 254 and the ram will be reversely pressurized raising the platen.

In normal operation of the baler, the baling chamber door is closed, and contacts 112' of switch 112 will be closed, and with the platen in its upper position and the access opening 146 therefore open, boxes, papers or whatever is to be baled are deposited in the baling compartment through such opening. When the chamber is full, the operator presses the start button 188 in FIG. 10, and with the programming switch 88-] set for automatic operation, the platen will descend, compact the material in the chamber and then ascend to its uppermost position. Actuating the stop switch stops the motor 251. When switch 88-1 is set for automatic operation, its contacts A, B, C, D and E are in closed position as represented by the mark 0 in the upper box accompanying FIG. 10. After the chamber is again filled the operator again presses the start button and the sequence repeats. This filling and compacting is continued until the chamber is filled with the compacted material. With the chamber thus filled, the compacted material is ready to be tied and removed from the chamber. To accomplish this, the programming switch 88-1 is turned to its manual down (man.down) position, and the start button pressed. Reference to the upper box accompanying FIG. 10 will indicate the positions of the contacts of -1 in the man.down condition. The platen thereupon descends until the back pressure in the ram as sensed by pressure switch 260 opens contacts N.C. thereof which serves to stop the pump motor 251. With the platen thus held against the compacted material as shown in FIG. 6, the operator opens the baling chamber door to the position shown in FIG. 4 exposing the compacted material. Baling wires W, see FIGS. 3 and 6, can then be threaded through the channels 31, 90 and 124 in the bed and back wall of the baling chamber and platen respectively, and the ends tied or clamped in any suitable manner as at T in FIG. 6. To prevent wires adjacent opposite ends of the bale from slipping off, a wire WS may be woven through and around the wires WS and secured, such that the bale is as shown in FIG. 6.

The programming switch SS-l is now turned to the manual up (man.up) position which shifts its contacts A, B, C, D and E to the positions shown in the upper box accompanying FIG. 10, and the start switch is then closed. The platen now ascends to its uppermost position and the bale is removed from the compartment in any suitable fashion. Thereafter the baling compart ment door is closed, the programming switch reset to the auto position, and the baler is ready to compact material for the next bale.

As more particularly disclosed in US. Pat. No. 3,677,175 of Neil Marvin, et al, assigned to the same Assignee as the instant application, means may be provided for facilitating removal of the bale from the chamber. As a bale may weigh upward of 700 pounds, manual removal of its to a pallet for storage can be difficult for the operator. Reference to said patent will show the steps of removal. In FIGS. 6 and 7 of the instant disclosure, the removal means for carrying out bale removal in accordance with the teaching of such patent is shown as including a lifting bar 200 telescoped into one of the members 122 of the platen 58, in particular member 122, which is offset from the centerline of the bale or platen toward the open end 202 of the chamber when the door is swung open to the position shown in FIGS. 4 and 6. Member 122' comprises a hollow channel. The end through which the bar projects may have an upwardly extending lip 204 which is removably received in a complementary notch 206 in the bar to prevent unintended longitudinal movement.

When not in use, the bar is lifted slightly and shoved into (to the right in FIG. 7) the channel for storage (the channel being long enough to accommodate the length of the bar) as during the compacting and bale forming operation of the baler. A ring 208 welded to the end of the bar serves as a finger hold for grasping the end of the bar to extract it from its stored position and dispose it as shown in FIG. 7. The ring may also serve as a stop or shoulder for trapping the end loop L of a bale extracting cable C. The cable has another loop L at its opposite end. The cable is threaded around the bale similar to the wires on the centerline or slightly to the right of the centerline of the bale, as shown in FIG. 6, and a slipknot formed by passing the cable through Loop L and hooking the loop L over the end of the bar as shown.

The extraction of the bar from its stored position and the threading and attachment of the cable to the bar as aforesaid accomplished when the platen is in its down position with the bale compartment door open and preferably immediately following securement of the bale wires W about the bale and prior to raising the platen during the previously described sequence in baler operation. In extracting the bar 200 from its stored position it may be necessary to manually raise the safety gate 148 which will then rest on the bar as shown in FIG. 7.

With the bale extracting cable attached to the bar as shown in FIGS. 6 and 7, the operator turns programming switch SS-l to the man.up position and the bale eject switch SS-2 from its of to its on]position which conditions contacts A, B, C and D of such switch as indicated in the lower box associated with FIG. 10. By closing the start switch, the pump motor 251 is energized as long as the operator holds the start switch closed and this causes the platen to ascend tensioning the cable C and lifting and swinging the bale out of the chamber. By turning the programming switch SS-l to the man.down position and closing the start switch, the platen is lowered to rest the bale on a pallet as more fully explained in said U.S. Pat. No. 3,677,175.

It will be noted that the baler will not operate to cause descent of the platen when the programming switch 85-1 is in its auto position and the baling compartment door is open because the NO. contacts of switch 112 will be open with the door open and consequently solenoid 254 cannot be energized upon depressing of the closure of start switch 188. The function and operation of the remaining switch contacts of FIG. 10 will be apparent to those skilled in the art in view of the above description and therefore need not be further described.

Shown in FIGS. 11-13 is another embodiment incorporating a second or auxiliary safety gate 280 in addition to the safety gate 148 previously described. The same reference numerals have been used in FIGS. 11-13 to identify identical parts. The auxiliary safety gate 280 is supported for vertically shiftable movement adjacent the gate 148 on the side thereof remote the platen 58, and is provided as an added safety feature.

The gate 280 comprises a rectangular frame 282 and a screen 284 similar in construction to gate 148, and is vertically reciprocable across the access opening in opposed U-channels 286 and 288 which may be secured to the outer faces of channels 166 and 168 which guide the gate 148 as by welding. Gate 280 has lugs 290, 292, 294 and 296 which ride in the channels 286 and 288.

Mounted atop the gate 280 are a pair of U-bolts or the like 198 and 300, to each of which is secured one end of a cable 302 and 304 respectively. On the side of the baler opposite the gates 148 and 280 are a pair of hollow cylinders, one of which is shown at 306, secured to the top of frame member 82. Within each cylinder is disposed a weight 308 having a hook eye 310 to which is secured the opposite end ofone of the cables 302 and 304. The cables are each entrained over a pair of pulleys 312 and 314 which are rotatably mounted on brackets 316 and 318 secured atop the frame members 44 and 48 of the baler. The weights 308 are sized to normally bias the gate 280 to its raised position shown in phantom at 280 in FIG. 12, the weights in this position of the gate resting on frame member 82 as shown in phantom at 308'.

To one side member of gate frame 282 there is se cured a mounting plate 320 having welded thereto a laterally extending bar 322 and a locking pin 324. A vertical arm 326 is fixed to the outer end of bar 322 and has a handle 328 secured to its lower end for manual manipulation by the operator of the baler. A clevis 330 secured to the bight of the channel 286 serves as a mounting bracket for a generally L-shaped latch 332 apertured to receive a pin 324, the latch having a projecting locking finger portion 336 engageable with pin 324 when gate 280 reaches its lowered position covering the baler access opening. The latch is biased in a clockwise direction as shown in FIG. 13, and is manually swingable in a counterclockwise direction to disengage pin 326 and release gate 280 for return to its normal raised position. As shown in FIG. 12, latch finger portion 336 has an inclined top surface 338 to cam the finger out of the way when engaged by pin 324 as the gate 280 is lowered, and then return to locking engagement with the pin 324 to retain the gate.

Referring to FIG. 12, there is shown a limit switch LS-3 having an actuating arm 340 which is engaged by weight 308 when the gate 280 reaches its fully closed position. LS-3 is a normally open switch whose contacts are closed when its arm 340 is shifted by engagement with weight 308.

In normal operation of the baler, with both gates I48 and 280 in their raised positions, and the chamber door 68 closed, the material to be baled is deposited in the baling chamber. When the chamber is full, the operator grasps handle 328 and pulls gate 280 down until pin 324 locks under latch 332, at which point weight 308 engages and shifts switch arm 340, closing the contacts of LS-3. Assuming the gate 280 is down and latched, closing LS-3, the operation of the baler is the same as previously described.

Referring now to FIG. 10, which is a schematic diagram of the ram control circuit, the position and function of LS-3 may be determined. With the circuit shown, closure of start contacts 188 energizes starter relay M. Switch LS-3, which is a normally open, held closed switch, is therefore placed in series with the relay M, thereby preventing energization of the relay unless LS-3 is closed, and thereby preventing actuation of the ram. In addition, if gate 280 is even slightly raised during ram descent, LS-3 will be opened by the downward movement of weight 308 (FIG. 12), thereby opening the circuit of relay M, and interrupting ram descent. The function and operation of the control is the same as previously described except for the addition of LS-3.

What is claimed is:

1. In a baler, a material baling chamber open at the top, a press platen vertically reciprocable through the open top of the chamber and having an upper position spaced at one side above an upper edge of the chamber providing an access opening for deposit of material into the chamber, a safety gate vertically shiftable across said access opening between an open position above the opening and a closed position covering the opening, means coupling the gate to the platen for vertical movement therewith and in advance of the platen during descent, said means including a lost motion coupling allowing descent of the platen relative to the gate and lifting of the gate during ascent of the platen, and control means responsive to descent of the platen relative to the gate prior to full closure of the gate to interrupt descent of the platen, characterized in that said control means includes a first element actuated by full closure of the gate and a second element actuated by a predetermined descent of the platen relative to the gate with such means interrupting platen descent upon actuation of the second element before actuation of the first element.

2. The invention defined in claim 1 characterized by a second safety gate vertically shiftable across said access opening adjacent the first mentioned safety gate on the side thereof remote said chamber; and means for shifting said second gate between an open position above the opening for deposit of material and a closed position covering said opening.

3. The invention defined in claim 2 characterized by counterweight means normally retaining said second safety gate in said open position, and latch means engageable with said second gate to releasably lock itin said closed position.

4. The invention defined in claim 2 characterized in that said control means includes a part actuated in response to complete closure of said second safety gate for preventing platen movement in the absence of part actuation.

5. In a baler, a material baling chamber open at the top, a press platen vertically reciprocable through the open top of the chamber and having an upper position spaced at one side above an upper edge of the chamber providing an access opening for deposit of material into the chamber, a safety gate vertically shiftable across said access opening between an open position above the opening and a closed position covering the opening, means coupling the gate to the platen for vertical movement therewith and in advance of the platen during descent, said means including a lost motion coupling allowing descent of the platen relative to the gate and lifting of the gate during ascent of the platen, and control means responsive to descent of the platen relative to the gate prior to full closure of the gate to interrupt descent of the platen, characterized in that said control means includes an electric control circuit for controlling ascent and descent of the platen and including a pair of electric switches to effect descent with one responsive to relative movement between the platen and safety gate to cause ascent of the platen and the other responsive to full closure of the safety gate to re nder said one ineffective.

6. The invention defined in claim 5 characterized in that said baling chamber includes a side opening door for removal of a formed bale and means for locking the door closed, and said control circuit includes a third switch responsive to failure of the door to be completely closed to prevent descent of the platen.

7. The invention defined in claim 6 further characterized in that said control circuit includes a programming switch operable to render ineffective said pair of switches and said third switch, and said control circuit including a manually operable fourth switch for causing manually controlled determined ascent and descent of the platen irrespective of the position of the baling chamber door or relative movement between gate and platen.

8. In a baler, a material baling chamber open at the top, a press platen vertically reciprocable through the open top of the chamber and having an upper position spaced at one side above an upper edge of the chamber providing an access opening for deposit of material into the chamber, a safety gate vertically shiftable across said access opening between an open position above the opening and a closed position covering the opening, a side opening door on said baling chamber for removal of a formed bale, a control circuit for controlling descent and ascent of the platen through a cycle of operation from the said upper position to a lowered position compacting material back to said upper position, said control circuit including switch means responsive to an obstruction preventing full closure of said gate to interrupt said cycle of operation and return the platen to said upper position, said circuit including a second switch means responsive to a failure to completely close said door to render inoperative said cycle of operation, and said circuit including manually operable switch means for raising and lowering the platen deter' mined increments irrespective of gate or door position. l l l l 

1. In a baler, a material baling chamber open at the top, a press platen vertically reciprocable through the open top of the chamber and having an upper position spaced at one side above an upper edge of the chamber providing an access opening for deposit of material into the chamber, a safety gate vertically shiftable across said access opening between an open position above the opening and a closed position covering the opening, means coupling the gate to the platen for vertical movement therewith and in advance of the platen during descent, said means including a lost motion coupling allowing descent of the platen relative to the gate and lifting of the gate during ascent of the platen, and control means responsive to descent of the platen relative to the gate prior to full closure of the gate to interrupt descent of the platen, characterized in that said control means includes a first element actuated by full closure of the gate and a second element actuated by a predetermined descent of the platen relative to the gate with such means interrupting platen descent upon actuation of the second element before actuation of the first element.
 2. The invention defined in claim 1 characterized by a second safety gate vertically shiftable across said access opening adjacent the first mentioned safety gate on the side thereof remote said chamber; and means for shifting said second gate between an open position above the opening for deposit of material and a closed position covering said opening.
 3. The invention defined in claim 2 characterized by counterweight means normally retaining said second safety gate in said open position, and latch means engageable with said second gate to releasably lock it in said closed position.
 4. The invention defined in claim 2 characterized in that said control means includes a part actuated in response to complete closure of said second safety gate for preventing platen movement in the absence of part actuation.
 5. In a baler, a material baling chamber open at the top, a press platen vertically reciprocable through the open top of the chamber and having an upper position spaced at one side above an upper edge of the chamber providing an access opening for deposit of material into the chamber, a safety gate vertically shiftable across said access opening between an open position above the opening and a closed position covering the opening, means coupling the gate to the platen for vertical movement therewith and in advance of the platen during descent, said means including a lost motion coupling allowing descent of the platen relative to the gate and lifting of the gate during ascent of the platen, and control means responsive to descent of the platen relative to the gate prior to full closure of the gate to interrupt descent of the platen, characterized in that said control means includes an electric control circuit for controlling ascent and descent of the platen and including a pair of electric switches to effect descent with one responsive to relative movement between the platen and safety gate to cause ascent of the platen and the other responsive to full closure of the safety gate to render said one ineffective.
 6. The invention defined in claim 5 characterized in that said baling chamber includes a side opening door for removal of a formed bale and means for locking the door closed, and said control circuit includes a third switch responsive to failure of the door to be completely closEd to prevent descent of the platen.
 7. The invention defined in claim 6 further characterized in that said control circuit includes a programming switch operable to render ineffective said pair of switches and said third switch, and said control circuit including a manually operable fourth switch for causing manually controlled determined ascent and descent of the platen irrespective of the position of the baling chamber door or relative movement between gate and platen.
 8. In a baler, a material baling chamber open at the top, a press platen vertically reciprocable through the open top of the chamber and having an upper position spaced at one side above an upper edge of the chamber providing an access opening for deposit of material into the chamber, a safety gate vertically shiftable across said access opening between an open position above the opening and a closed position covering the opening, a side opening door on said baling chamber for removal of a formed bale, a control circuit for controlling descent and ascent of the platen through a cycle of operation from the said upper position to a lowered position compacting material back to said upper position, said control circuit including switch means responsive to an obstruction preventing full closure of said gate to interrupt said cycle of operation and return the platen to said upper position, said circuit including a second switch means responsive to a failure to completely close said door to render inoperative said cycle of operation, and said circuit including manually operable switch means for raising and lowering the platen determined increments irrespective of gate or door position. 